The present invention relates to an apparatus for manufacturing a magnetic disk to be rotatably fitted in a cartridge, and more particularly relates to an apparatus for manufacturing a magnetic disk in which an adhesive is applied to the flange of a center core.
FIG. 5 shows a magnetic disk and cartridge unit 1 including a magnetic disk made of a center core 3, which is provided for positioning and chucking purposes, a magnetic sheet 4 adhered to the core, and a cartridge composed of a pair of plates 2 for housing the disk. Such a disc is disclosed in Japanese Unexamined Published Utility Model Application No. 186565/85.
The process of manufacturing the magnetic disk and cartridge unit 1 will be described with reference to FIG. 6. One of the primary steps is an adhering step 5 in which the center core 3 and the magnetic sheet 4 are adhered to each other to form the magnetic disk. Another important step is an assembly step 6 in which the magnetic disk is fitted in the plates 2 of the cartridge. In the adhering step 5, the center core 3, having a flange with an adhesive thereon, is passed through a drier 5b in a direction A of conveyance to partially dry the adhesive, and then magnetically attracted to the attracting portion 8c of an arm of an adhering oscillatory handler 8a. The arm is swung in a direction C to move the center core to a magnetic sheet feed section 9 so that the core is fitted into the circular center hole 4a of the magnetic sheet 4 with the core and the sheet adhered to each other to constitute the magnetic disk 7, which is then conveyed to a prescribed position. The magnetic disk 7 is magnetically attracted to an attracting portion 8d of one of two arms of a double-armed oscillatory handler 8b and then moved to a prescribed accumulating position. The disk 7 is thereafter magnetically attracted to the attracting portion 8e of the other of the arms of the handler 8b. The latter arm is then swung in a direction C so that the disk 7 is sent to the assembly step 6. It should be noted that the latter handler 8b need not be double-armed, but rather may have only one arm.
One of the plates 2 for the cartridge is conveyed to the assembly step 6 in the direction of arrow B in advance of the disk 7. Therefore, the disk 7 is conveyed to a position above the plate 2 by the handler 8b prior to termination of the magnetic attraction of the disk 7 to the attracting portion 8e of the handler 8b so that the disk is placed in the plate. The plate 2 containing the disk 7 is then sent to the next step of the process.
The process in which the adhesive is used to adhere the center core 3 and the magnetic sheet 4 to each other in the above-described manner without using a double-sided adhesive tape has been often adopted in recent years. If the adhesive is a solvent type or emulsion type, it must be subjected to drying after being applied to the center core 3, as described above. Therefore, a drying furnace must be provided for partially drying the adhesive before the core and the magnetic sheet 4 are adhered to each other using the adhesive. If the adhering operation in the step 5 were stopped due to, for example, an assembly operation in step 6, the center core 3 would be caused to remain in the drying furnace for an excessive period of time, resulting in poor adhesion of the adhesive to the magnetic sheet 4 to greatly reduce the adhering strength of the adhesive to the sheet. Also, if the temperature in the furnace is high, the quality of the adhesive would likely change while in the furnace so as to alter the condition and quality of the adherence of the core 3 to the sheet 4. To prevent the condition and quality of adherence of the core 3 to the sheet 4 from being deteriorated due to the presence of the core in the furnace, the magnetic disks 7 can be temporarily stored in the accumulating position.
Since the arms of the oscillatory handlers 8a and 8b are reciprocated and it is necessary to set a time for partially drying the adhesive and control the heating thereof in the furnace, the apparatus for practicing the adhering step 5 and the assembly step 6 has a basic drawback in regard to the inability to increase the speed of the process so as to enhance productivity.
There is also known an apparatus for practicing a process of manufacturing a magnetic disk and cartridge unit with a double-sided adhesive tape, instead of a solution-type adhesive. Since the apparatus does not need to control the temperature of the adhesive by the use of a heating device, the speed of the manufacture can be increased by adopting a rotary assembly section which rotates 360 degrees, rather than oscillating back and forth as the oscillatory handlers 8a and 8b discussed above.
If an apparatus as productive as the above-mentioned apparatus having the rotary assembly section were available to manufacture a magnetic disk and cartridge unit using a solvent type adhesive, productivity could be much improved. However, there are a number of problems in developing such an apparatus. The apparatus having a rotary assembly section includes a plurality of stations such as a center core feed station, a double-sided adhesive tape feed station, an inspection and an adhering station, and a holder which holds the center core. The holder is not only moved up and down but also rotated. If a heating device is provided for each of the stations, there are problems, however, that the adhesive solidifies due to the lack of heat where the holder is stopped, and the apparatus is relatively complicated. If the holder is not of the magnetic attraction type but of the vacuum attraction type, there is a problem that air leaks due to the center core structure making it very difficult to produce a sufficient heating effect. If the entire rotary section of the apparatus is heated, there is a problem in that a very large heating system must be provided, resulting in an apparatus that is uneconomical. For these reasons, the rotary-type apparatus has not been used to manufacture a magnetic disk with a solvent-type adhesive.
Accordingly, it is an object of the present invention to provide an apparatus for manufacturing a magnetic disk and whose use results in as low material cost of the disk as a conventional apparatus for manufacturing a magnetic disk with a solvent-type adhesive and as high productivity as a conventional apparatus for manufacturing a magnetic disk with a double-sided adhesive tape.